The present invention relates to a device for forming an inserting hole for an endoscope, and more particularly to a device used for forming an inserting hole for medical examination or treatment of various kinds of cholangia diseases, nephrosis and the like which enables the use of an endoscope just after the drainage and can surely prevent a drainage tube from dislodging off in the abdominal cavity.
In recent years, improvement has been made in the field of endoscopes so that percutaneous treatments using endoscopes have been carried out for various sickness in the bile duct, cholecyst, renal pelvis or ureter. That is, fibrous cells are formed around a drainage tube as a reaction of the organism to foreign material by percutaneously inserting the drainage tube having a diameter of 5 to 6 mm (1 mm is 3 frenches) necessary for the insertion of the endoscope into duct organs such as bile duct, cholecyst, renal pelvis and the like. A fistula is thus formed and the endoscope is put in or out through the fistula to carry out the treatment.
In the conventional technique, a small diameter tube (for example 7-french tube) is gradually exchanged at an interval of few days to one week for such tube as having one or 2 french larger outer diameter in about an month, whereby forming a large diameter fistula allowing the insertion of endoscopes. Thus, the conventional method has problems that it gives a great pain to a patient and is time-consuming.
With respect to the technique of dilation, USP 4,705,041 by Kim discloses a dilating tube for sphincter of Oddi. The Kim's tube comprises a guide catheter having an expandable tip and a plurality of dilators each having an enlarged tip portion at one end and a handle portion at the other end.
However, the Kim's tube is merely a device which dilates a narrowed portion and accordingly cannot be used for newly forming a fistula. Though the tip of the guide catheter in Kim's tube is made expandable to fascilitate the blind operation, such expandable tip is not necessary in the dilating operation using a device of the present invention because the operation of tubes is performed under fluoroscopy in the case of the device of the present invention.
Further, the ditator in Kim's tube has an enlarged portion at its end only for being pushed blindly to duodenum and dilating sphincter of Oddi after inserting a guide catheter through a cut bile duct during the ventrotomy.
The Kim's dilator, accordingly, cannot dilate a catheter tract in the liver tissue, in which veins and bile ducts extend like a mesh, in the way in which the dilator pushes its way through the tissue. Moreover, there are caused a hemorrhage from a tract and a leakage of bile, since the tip of the Kim's dilator is enlarged, and a difference in level between the enlarged tip and a portion succeeding the enlarged tip checks sufficient fitting between the dilator and the tract whereby generating a gap therebetween.
Still further, it is not easy to operate the Kim's dilator since it has a handle portion for operation and therefore is made long.
In order to solve the above-mentioned problem, the present inventor proposes a set for expanding a fistula for bile drainage (Japanese Unexamined Utility Model Publicatation No. 78938/1987). The set comprises a small diameter tube allowing a guide wire to pass through a center thereof, a medium diameter tube covering an outer periphery of the small diameter tube, and a large diameter tube covering the outer periphery of the small diameter tube and having an outer diameter larger than that of the medium diameter; and is characterized in that an outer diameter of each tip portion of the small diameter tube, the medium diameter tube and the large diameter tube is gradually reduced toward ends thereof to be taper-shaped.
Thanks to the use of the above set for expanding a fistula for bile drainage, a fistula is expanded only in about three to five minutes and the large diameter drainage tube can be inserted into the expanded fistula while, in the conventional technique, catheters are required to be exchanged four or five times at an interval of few days to one week.
In the various treatments using an endoscope such as lithotripsy, polypectomy and the recovery of the removed tissue, however, it is necessary to completely pull out the endoscope many times while holding the tissue or calculus. Therefore a fistula between the chest wall and he surface of the liver or between the retro abdominal wall and kidney is required to securely adhere. A large diameter drainage tube having a diameter of 16-french to 18-french is required to be kept in the fistula to complete the formation of a strong fistula. Such method gives a great pain to a patient.
It is an object of the present invention to provide a device for forming an inserting hole for an endoscope capable of reducing the damage of human body organization as much as possible and capable of not only expanding a fistula but also carrying out a treatment using an endoscope in a short time.